Safari/iOS/iPadOS Array Allocation Sinking Crash pre-26.1
CVE-2025-43421 Published on November 4, 2025
Multiple issues were addressed by disabling array allocation sinking. This issue is fixed in iOS 26.1 and iPadOS 26.1, macOS Tahoe 26.1, visionOS 26.1, Safari 26.1. Processing maliciously crafted web content may lead to an unexpected process crash.
Vulnerability Analysis
CVE-2025-43421 can be exploited with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.
Weakness Types
Out-of-bounds Read
The software reads data past the end, or before the beginning, of the intended buffer. Typically, this can allow attackers to read sensitive information from other memory locations or cause a crash. A crash can occur when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string. The expected sentinel might not be located in the out-of-bounds memory, causing excessive data to be read, leading to a segmentation fault or a buffer overflow. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent read operation then produces undefined or unexpected results.
What is a Memory Corruption Vulnerability?
The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.
CVE-2025-43421 has been classified to as a Memory Corruption vulnerability or weakness.
Products Associated with CVE-2025-43421
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Affected Versions
Apple Safari:- Version unspecified and below 26.1 is affected.
- Version unspecified and below 26.1 is affected.
- Version unspecified and below 26.1 is affected.
- Version unspecified and below 26.1 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.